jetblast

how fast do the stock rings wear on a stock block with the 150hp shot? and is there a limit to how much you can spray on a 10kmi motor as opposed to a 80kmi? considering ring gap encreases as the engine gets older. the reason i ask is because the dip stick started popping out just a hair soon after i began spraying the 150 with good timing and fuel. blowby seemed to worsen last season when i went lean a few times, the dipstick popped out about an inch. now this season i have sprayed 100w about 28 times no progression and i have not noticed any more changes in how far the dipstick comes out. i know a compression test and leak down test will tell me how badly worn the rings are.

w3s1c0a5t

iTrader: (3)

Bump. Good question I would like to hear input on aswell.

kinglt-1

iTrader: (26)

I have herd to keep the afr's in the mid 11's on the stock bottom end and it will live a long time on a 150. How long, nobody can accurately say. Also you can run in the lower to mid 12's afr and make more power, but at the cost of engine wear. The stock piston and rings start getting to hot at those afr's. Now if your forged, 12.2-12.5 afr might be acceptable.
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...

jetblast

i know the rings are tired, only a compression test will tell me if there is a particular cyclinder out of whack, i'm sure the overall results won't be close to a new set of rings. many folks here say they have been spraying 150w for a long time but, none have said if blowby has gotten worse. i am positive that i had a really safe tune when i sprayed the 100w and then the 150w [ 11.2afr and 18for the 100 and 15 for the 150] with vp103. i never had a breather sys. installed other than the stock set-up. i started spraying in 07, and in 08 i went very lean a total of 5 times upwards of 14.7 to about 16 or a bit higher. this season i sprayed a total of 28 times at the very minimum. with no mercy on the motor, i had no progression, ramp or delay and yet the motor still very fast. so maybe the question should be: DID ANYONE EVER RUN THE MOTOR UNTIL THE RINGS COMPLETLEY WORE OUT?

kinglt-1

iTrader: (26)

if you have blowby causing the dipstick to pop out, then a ring(s) are wore out. Again do a compression test, if they are more than 20% down, rebuild it. I personally would not keep spraying a hurt motor, some most likely have. The part where you went super lean 5 times most likely caused this. What caused you to run so lean?

jetblast

the dip stick started popping before the going lean problem, it never really has gotten any worse. i had a fuel noid intermittenly not opening, changed to nx and haven't had a problem since.

jman54002

iTrader: (11)

I use to keep a record of the compresion on each cylinder and after each track day compair what it is and what it was. A great tool to watch for damage. If the motor is using oil be careful that it does detonate on the oil in the combustion camber. oil will make it easier to detonate. just my .02

ShiznityZ28

iTrader: (11)

11.5 is not safer than 12.05 ... The correct A/f is the correct a.f anything else is incorrect and will wear a motor out.

kinglt-1

iTrader: (26)

How is that?

Pwebbz28

iTrader: (31)

Too rich and too little timing is just as bad as too lean and too much timing. 11.5-12.0 is pretty good for nitrous though.

If you can get it more between 11.8-12.0 it would be better.

kinglt-1

iTrader: (26)

Right, wich was basically my point. I was just saying that by leaning it out a bit, more power can be had. Keeping it on the rich side is a bit is safer tho. Too rich is in the 10's, too lean is 12.4+, depending on setup...

jetblast

you guys need to research this mans threads. and for anyone that happens to run into this thread , the correct fuel [afr] is when a pencil think line appears on the porcelain of the plug. the other and perhaps just as important, in my book, more important, is the timing the motor actually needs, which is very often too advanced. like i said i had a horrible tuning seaon in 08 due to the bottle tilt and so i often hit low 11s afrs at the end of the track. that could explain why i have exessive blowby. these engines were not designed with high combustion temperature in mind, i have searched and not many reports are found of someone logging and tuning safely, while maxing out the shot and blowing it up. i was just digging to see if anyone has had such good luck, to beat the motor with max n2o shots and live to tell about it, then tear it down and see how much abuse the rings could take with the proper tune.

kinglt-1

iTrader: (26)

If you would take the time and do research, you would see many run 150 shots on stock rings and live. I agree afr's are not the whole equation for tuning, obviously reading the plugs and timing are two critical factors. My point about afr's was that, 11.5-12.0 is a common range, but yes read the plugs for verification. I gusss it suprises me that you are running 10's, but yet you are asking questions that it seems you should know. The stock bottom end is good to 600whp, anything more and its time for forged components. Thats how I would dictate how much to spray!

jetblast

ShiznityZ28 makes so much sense that too rich is also not great. i gues that's what my motor was exposed to one too many times in 08, washing the walls. oh well. this is my first hot rod and so i'm new to the n2o scene. at least, now i've got full control of my afr curve so it never goes much richer at the end.

kinglt-1

iTrader: (26)

Hey Im learning too. I do agree Shiznity does know his stuff, I have followed quite a few of his posts! I should of reworded my first post about afr's because I see where there can be some confusion. Yes too rich is just as bad as too lean. An overly rich condition can lift the rings causing your issue. Now I don't mean to come off as an expert, because Im new too nitrous aswell. Im just sharing info that I have learned from researching nitrous. Live and learn right!

jetblast

i guess now i have a choice to make, either quit spraying and do a compression ck. or go with my stubborn instincts and see if the motor will hold the 200w shot. if it lives, my goal is completed.

slammin86

iTrader: (4)

If the damage is already done then keep spraying it.

If you do some research, you will see that these motors tend to pop dipsticks under boost conditions. There is blowbye, and the crankcase becomes pressurized. The pressure has to go somewhere.

Have you noticed any oil loss between changes?

G Engines

If you have that much crankcase pressor that your pushing the dip stick out YOU HAVE A PROBLEM. It is cheeper to fix it now than it is to burn a piston or break one and have to buy a new block. Yes the damage is already done but it can always get worse. I have seen it and repaired it. BE SMART save your self some money and fix it before it's too late.

IWGF

iTrader: (6)

I'm with G engines on this one... Just say **** it, do a compression test, allocate some money to go forged internals, then get back to sprayin

jetblast

no oil loss man. yeah, i have been searching for ever to see what makes these engines tick, i know there are many with fi who blow the stick out due to blow-by. generally speaking the higher the pressures the more blow-by, i have on one track occasion been able to generate more cyclinder press. by just leaning it out gradually, pass after pass, more than it needs to be and the result was that the stick completely popped out. it was just hanging there. i have not been very agressive with timing until this season. i could use a vacum pump for sure, but at this point that would just mask the problem. thanks for the info though. i have seen some guys put these stock bottoms to the test with a relatively agressive tune, too much timing, a hair too rich, big *** shots, and the motor takes it pretty damn well. not sure if it's due to the low oct tables been left stock which would buy you some time, and or both, the engine itself is very stout.